From Brecon: just before the cattle grid marking the end of the reserve is a pond. At the pond leave the single track road by heading left. follow the field boundary (you should end up leisurely curving around to end up walking back towards Brecon) and eventually the stone will come into view (5 minutes walking).

Just under 1m in height. Old Red Sandstone, but unlike the square Mountain Centre 1, this stone is more like a boulder, deeply eroded and pitted, much like the Rollrights.